Manufacture of compressed substances from aromatic amines, aldehydes, and filling materials



Patented Jan. 29, 1935 MANUFAQITUEE OF COMPRESSED i see STANCES'FROM AROMATIC AMENES, AL- DEH EZDES, AND FllL-LXNG P/EATERIALS Hermann Burmeister, Hennigsdorf, near Osthavelland, Germany, assignor to General Electric Company, a corporation of New York No Drawing. Application July 19, 1932, Serial No.

- 623,459. in Germany July 28, 1931 l Claims.

The present invention relates to the manufacture of compressed substances from aromatic amines, aldehydes and filling materials.

Such compressed substances may be produced according to previously known methods of manufacturing-in different ways: For instance, an aniline-formaldehyde resin can be obtained in a strong mineral acid solution, and this resin is insoluble and non-fusible and can be used as a compressed or molded substance after being mixed with filling materials. Further it has been proposed to manufacture soluble and fusible resins which can be hardened to an insoluble and infusible stage, and work up their solutions or fusions with filling materials to form compressed materials and composite paper or cardboard.

These methods always involve several steps, such as the manufacture of the resin, the refining of the same, and the working up of the resin with the filling materials to form compressed substances.

It has been surprisingly and unexpectedly discovered that during the reaction between amines and aldehydes a solvent can be dispensed with entirely. At the same time it has been observed that the reaction is not delayed by the addition of large quantities of inert filling materials. These discoveries have led to further research on the manufacture of compressed substances and it has been demonstrated that compressed substances can be manufactured directly and by a single process from a mixture of resin-forming components and the filling materials, and that these compressed substances satisfy all requirements.

Furthermore it has been found that in this way it is also possible to produce compressed materials with good flow determined by the fusible state of the binding material. It has also been found that rapidly hardening compressed materials can be formed by adding reaction accelerators; and colored substances by adding coloring materials. Additions of a plastic nature can be worked into the substance without the hardening reaction being disturbed.

The great advantage of such a process lies not only in the fact that solvents, by-products, acids and alkalis are eliminated, but also in the fact that the reduction of the steps heretofore necessary and the simplification of the apparatus bring about a considerable saving.

For manufacturing compressed materials in accordance with the invention, it will be convenient to use a roller which can be heated, and on which a previously prepared mixture of resinforming components and filling materials is rolled. The raw materials however can be placed on the roller so thatcondensation and mixing take place simultaneously. The time required for rolling and the temperature arearranged so 5 that on the one hand the water occurring during condensation evaporates from the rolled sheets, and on the other hand the compressed. material. has a more or less high degree of fiow. In this a Way the most varied aromatic amine and the most varied aldehyde combinations can be united to form resins and thus compressed substances, as the following examples show:

Example 1 15 125 parts wood meal are worked up with parts formaldehyde, 93 parts aniline, 8.3 parts phthalic acid (all by weight) and coloring matter in a rolling mill, the temperature of which is kept between and 140 C. until the material runs off the rollers in compact rolled sheets. If the rolled sheets are Worked up further on the roller the compressed materials retain their compressibility longer, but their fiow decreases.

Example 2 25 parts wood meal are worked up with '72 parts naphthylamine, 100 parts croton aldehyde, 10 partsbenzoic acid, (all by weight) as well as the necessary coloring material on a heated roller until sheet consistency. After pulverization the substance is ready for compressing.

The contact substance used in this process is not only intended to accelerate condensation but also to accelerate polymerization of the resin under pressure. It has been shown, in particular, that the heat resistance of the compressed materials obtained is increased by the presence of a small quantity of acid as contact substance. The acid to be chosen as contact substance de- 40 pends on the nature of the compressed material, e. g. sulphuric acid is unsuitable for compressed substances of wood meal. If strong acids, e. g. chlor-acetic acid are used as contact substance, then there is an increase in the Marten number of the test bars in the compressing process. The Marten number is a number obtained in accordance with Martens method which is described in Vorschriftenbuch des Verbandes Deutscher Elektrotechniker (18th edition), p. 198 et seq. It substantially consists in subjecting a rod, made of the resin to be treated, to a constant bending momentum at the same time gradually increasing the temperature of the rod and determining the temperature at which a predetermined degree satisfactorily without a contact substance, as the following example shows.

Example 3 125 parts wood meal are mixed in a mixing mill with parts paraformaldehyde, finely, milled, and 93 parts aniline, (all by weight) and rolled on a roller several times at a temperature increasing slowly from to about C.

It is advantageous to split up the process into several stages, so that a partial condensation product is produced, which is then worked up with further quantities of aldehyde to the hard stage and which can be hardened until the substance is insoluble and infusible.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A process for manufacturing compressed substances which comprises reacting a primary aromatic amine, an aldehyde and filling material in the absence of solvents and under heat and mechanical pressure. I

'2. A process for manufacturing compressed substances which-comprises reacting a primary aromatic amine, an aldehyde and a relatively large proportion of filling material, in the absence of solvents, under heat and mechanical pressure.

3. A process for manufacturing compressed substances which comprises reacting a primary aromatic amine, an aldehyde, a relatively large proportion of filling material, and condensation and polymerization accelerators by subjecting the mixture of ingredients without solvents to the action of heated rollers until an insoluble, infusible product results.

4. A process for manufacturing a resinous product which comprises reacting in the absence of solvents and under heat and mechanical pressure, aniline and formaldehyde with a relatively large proportion of filler.

HERMANN BURMEISTER. 

